Sterilization containers of this type are usually used for sterilizing medical instruments. For this, such sterilization containers have a container cover, which is detachably tightly connected to a corresponding lower housing of the sterilization container. In order to guarantee “aeration and ventilation” in closed sterilization containers, such a sterilization container has in one of its wall areas gas-exchange openings, which are covered during operation on the inside by means of a filter sheet. Such a filter sheet usually consists of paper, a nonwoven fabric or textile material. This filter sheet is replaced on a regular basis with increasing duration of operation and/or in case of a change in the instruments to be sterilized.
For this, the filter sheet is held by a pressure washer which meshes detachably with a frame element arranged on the inside at the wall area, surrounding the gas-exchange openings in a ring-shaped manner. The detachable connection between the pressure washer and frame element is established by a bayonet connection, which is formed from bayonet catch elements or from bayonet connection elements, which can be mutually meshed with one another, at the pressure washer, on the one hand, and, at the frame element, on the other hand. To seal the pressure washer against the wall area of the sterilization container or against the frame element, a preferably elastic sealing ring is provided that is mounted on the wall side in a circumferential ring groove of the pressure washer. In the mounted state, the sealing ring presses against the filter sheet, which is preferably inserted—with a relative accuracy of fit—into the ring-shaped frame element. The pressure washer, filter sheet and frame element thus form a type of filter unit.
By means of the bayonet connection formed between the frame element and the pressure washer, the pressure washer may only be released from the frame element by means of a rotating relative motion and can again be meshed with same in a positive-locking manner rotating in the opposite direction. Since the sealing ring of the pressure washer presses tightly against the filter sheet and the pressure washer is accordingly to be braced under axial prestress against the filter sheet especially during insertion, this routinely leads to a shifting of filter sheet and/or to its damage.